The present invention concerns a filtering medium, a method for the production thereof, the use of said filtering medium and a method for reducing the content of multiple contaminants simultaneously in fluids by means of said filtering medium through a physical barrier, a chemical process or biological process, wherein said filtering medium consists of or comprises at least one of the following: a mixture (A) containing a major part of an iron-based powder and a minor part of a copper based powder, an iron-copper powder alloy (B), and an iron-based porous and permeable composite containing copper (C).